1. Field of the Invention
This invention relates to an alignment device for the manufacture of semiconductor circuit elements, and more particularly to an alignment device for bringing a mask and a wafer into intimate contact with each other.
2. Description of the Prior Art
Intimate contact between a mask and a wafer has been accomplished usually by rendering air-tight the clearance between a mask supported by a mask supporting member and a wafer supported by a wafer supporting member movable toward the surface of the mask, by evacuating the clearance between the mask and the wafer by means of a vacuum pump, and by moving the wafer supporting member toward the mask with the aid of the differential between the vacuum pressure and the atmospheric pressure or by bringing the photomask and the wafer into intimate contact with each other with the aid of a force created by the pressure differential.
However, this contact method, as will later be fully described by reference to the accompanying drawings, has suffered from a disadvantage that the mask is forced upwardly by the peripheral portion of the wafer and accordingly, the mask is warped toward the surface opposite to the surface of the wafer which is in intimate contact with the mask, namely, the free surface of the wafer, to create a non-contact portion between the central areas of the mask and wafer or to cause warping of both the mask and the wafer, thus preventing the mask pattern from being accurately printed.